HPLC Method for Simultaneous Determination of Nicotinic Acid, Nicotinamide, Pyridine Dicarboxylic Acid, Ethyl Methyl Pyridine and Ethyl Nicotinate on Zodiac HST OG Column

Nicotinic acid, also known as niacin or Vitamin B3, is an essential nutrient synthesized from tryptophan by plants and animals. It is widely used as a dietary supplement to treat pellagra. Nicotinamide, a derivative of nicotinic acid, is an important component of coenzymes such as NAD and NADP⁺, playing a key role in cellular metabolism.

Pyridine dicarboxylic acid (PDA), also known as dipicolinic acid (DPA), is associated with bacterial endospore heat resistance and is instrumental in the preparation of transition metal complexes used in ion chromatography. Ethyl methyl pyridine serves as a common intermediate in the synthesis of nicotinic acid, while ethyl nicotinate (the ethyl ester of nicotinic acid) is used in topical formulations for relieving ligament, joint, and muscle pain.

These five structurally related organic compounds were successfully separated and analyzed using the Zodiac HST OG mixed-mode column. The method employs a simple gradient mobile phase composed of water, acetonitrile (MeCN), and sulfuric acid (H₂SO₄) as the buffer. The separation is monitored by UV detection at 250 nm, offering high resolution and excellent peak symmetry.